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php中0,null,empty,空,false,字符串关系详解在一个项目中遇到了一个奇怪的问题，耗费了我不少时间都没有解决，最终调试发现是判断的问题—-关于0和 ‘ ‘ (空单引号,为好...在一个项目中遇到了一个奇怪的问题，耗费了我不...
Putting an if-elif-else statement on one line?
...st likely violate PEP-8 where it is mandated that lines should not exceed 80 characters in length.
It's also against the Zen of Python: "Readability counts". (Type import this at the Python prompt to read the whole thing).
You can use a ternary expression in Python, but only for expressions, not f...
Aligning text and image on UIButton with imageEdgeInsets and titleEdgeInsets
... already does so we simply need to adjust the spacing.
CGFloat spacing = 10; // the amount of spacing to appear between image and title
tabBtn.imageEdgeInsets = UIEdgeInsetsMake(0, 0, 0, spacing);
tabBtn.titleEdgeInsets = UIEdgeInsetsMake(0, spacing, 0, 0);
I also turned this into a category for ...
Get last n lines of a file, similar to tail
... till it's found the right number of '\n' characters.
def tail( f, lines=20 ):
total_lines_wanted = lines
BLOCK_SIZE = 1024
f.seek(0, 2)
block_end_byte = f.tell()
lines_to_go = total_lines_wanted
block_number = -1
blocks = [] # blocks of size BLOCK_SIZE, in reverse orde...
How to round a number to n decimal places in Java
...ngMode(RoundingMode.CEILING);
for (Number n : Arrays.asList(12, 123.12345, 0.23, 0.1, 2341234.212431324)) {
Double d = n.doubleValue();
System.out.println(df.format(d));
}
gives the output:
12
123.1235
0.23
0.1
2341234.2125
EDIT: The original answer does not address the accuracy of th...
How do I ZIP a file in C#, using no 3rd-party APIs?
...|
edited Mar 24 '11 at 13:03
adrianbanks
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a...
Create list of single item repeated N times
...
809
You can also write:
[e] * n
You should note that if e is for example an empty list you get a...
0.1 float is greater than 0.1 double. I expected it to be false [duplicate]
...loat. float has 24 binary bits of precision, and double has 53. In binary, 0.1 is:
0.1₁₀ = 0.0001100110011001100110011001100110011001100110011…₂
^ ^ ^ ^
1 10 20 24
So if we round up at the 24th digit, we'll get
0.1₁₀ ~ 0.00011...
Python Infinity - Any caveats?
...-a-number (NaN) values from simple arithmetic involving inf:
>>> 0 * float("inf")
nan
Note that you will normally not get an inf value through usual arithmetic calculations:
>>> 2.0**2
4.0
>>> _**2
16.0
>>> _**2
256.0
>>> _**2
65536.0
>>> _**...